/Engine/Plugins/Experimental/GeometryScripting/Source/GeometryScriptingCore/Public/GeometryScript/MeshNormalsFunctions.h
Note that this function requires that some normals/tangents already exist on the TargetMesh. If this is not the case, functions like SetPerVertexNormals and ComputeTangents can be used to initialize the normals/tangents first.
static [UDynamicMesh](API\Runtime\GeometryFramework\UDynamicMesh) * UpdateVertexNormal ( [UDynamicMesh](API\Runtime\GeometryFramework\UDynamicMesh) * TargetMesh, int VertexID, bool bUpdateNormal, FVector NewNormal, bool bUpdateTangents, FVector NewTangentX, FVector NewTangentY, bool & bIsValidVertex, bool bMergeSplitValues, bool bDeferChangeNotifications )